Demulsification of water-nitro-xylene emulsion



Patented Mar; 7, 19150 'l v l 499,927? l l nnMULsIF'JCATIoN 0F wailing-NITRO.

- XYLENE'EMULSION` AiithurEMartin, Bellower; C1i.,.ass ignor isos:l

Shelli-1lDevelopment;- Company, San lirancisco;i Galifinaocoifporationiof Delawariei.,l

allaline inorganic salts are-most eiective'when coming;unneutralize@reaction-aproduct. employed as comminuted solids or in anhydrous G-,ontnuousioperatiomisaalsoipirefrredibecausef orfsubstantially anhydrous form. 60 the emulsion is continuously withdrawn and de mulsiiied shortly after the emulsion forma-v tion. By thismeans the-stable emulsion is broken n with greater relative ease since it does not undergo compaction and further increase in staof Xylenols. The reaction product was washedy with Water and inorganic acidic material Was for the most part thereby removed. The resultant,

as yet unneutralized, reaction product was sepaterials were neutralized at about 90. C. by in` timately contacting the preheated product with about'5'0% of its own volume of a hot 20% ,by

weight sodium carbonate solution.

The resultant aqueous phase was separated from the thus-neutralized reaction product. The remaining nitroxylene phase retains too high a concentration of sodium nitro-phenolate type of salts;` these salts are explosive and are dangerous in any subsequent distillation. The separated nitroxylene phasevis washed with Water at about 90 C. to remove additional amounts of the objectionable phenolate salts and additional quantities of other by-products. During this water-washing. step, a Stable emulsion of the type described herein, is formed. To obtain faster washing action, the wash water was at about 90 C., although a stable emulsion forms in varying amounts irrespective of the particular washing temperature. This emulsion generally contains 2 wt. per cent or more ofrthe total nitroxylene. The nitroxylene content of the emulsion ranges from about 35% to about165% in different instances.

The thus-formed stable emulsion accumulates at the topof the nitroxylene in any separator or,v

storage vessel and is separated as such. 4When portions of the 4- emulsion were boiled for long temperature of water, i. e, about 100 C; Excellent. results were obtained between about 40 C. and about 50 C. On settling, thealkaline aque-l adjustment to the proper 'alkalinity y l The resultant separated nitroxylene phase from the broken emulsion was removed. It was clear i and substantially anhydrous, i. e. there was less than about 0.3 wt. per cent of waterv therein.

this recovered and purified nitroxylene phase was found s afe and suitable for distillation.

I claim as my invention:

1. The process of recovering mono-nitroxylene froma persistent andstable, substantially neutral, emulsion thereof with water, said emulsion containing from about 35 to 65% by weightfof nitioxylen'e. which comprises intimatelycontact` .y ous phase separated as the lower layer which can be'recycled to the rst alkaline wash step after 'insoluble and aqueous alkali-insoluble#nitro-hy ing said emulsion at a temperatureo'f kfrom about i 35 C. to l'about 100.C. with frm'akout 10 to 30% by weight, based on the water content of said femulsion, of solid sodium carbonate, in amount selected to produce an aqueous solution with the `water content voi the emulsion having a specic gravity greater than that of the nitroxylene under the conditions ofthe contacting, thereby eii'ecting de-emulsication, and recovering a separated phase of nitroxylene.

. 2. The process of recovering mono-nitroxylene from a stable, substantially neutral, aqueous emulsion thereof which comprises intimately contacting said emulsion, at a temperature above the melting point of said nitroxylene, with solid sodium carbonate in an amount suflicient` to form asolution with the water content of said-y enl ul,, sion, having a greater specic gravity' than said;- nitroxylene under the conditions of ,said con--` tacting, thereby effecting de-emulsiiication, an recovering a separated nitroxylene phase.l i 3. The process ofrecovering a relatively water-Q.. insoluble and aqueous alkali-insolublenitrofaromatic hydrocarbon from a stable, substantially neutral, aqueous emulsion thereof which com--l prises intimately contacting said emulsion, at a temperature above the melting point Vof the nitrc'J-f aromatic hydrocarbon, with a solid alkali metal p' carbonate in an amount suicientto form asoluf'l'. tion withthe water content of said emulsion hav- "temperature above the melting point of 'sfaid` nitroaromatic compound with a water-soluble i'nf organic alkaline agent in' an lamount suilicien l, to form a solution with the water conftent'of 'saidjl emulsion, having a greater specific gravity than, said nitroaromatic compound at they temperature"l of thecontacting, thereby effecting de-emuls'i'fif' cation and recovering a separated phaseIv of said; nitroaromatic compound. l

5. The process of recovering a relatively water drocarbon frorna stable, substantiallyy 'neutralA aqueous emulsion thereof whichl c'o'rnprises'in timately ,contacting saidv emulsiomat a tempe" ture above the melting point of'saidnitro-hydro carbon, with a water-soluble'inoganic alkaline". agent 'in an amount sucient to 'form a solution" with the water contentof said emulsion having" avgreater specic gravity than said 'nitroe-l'iydr'ol carbon, at vthe .temperature of said. contacting', thereby eiecting de-emulsication and recover a'separated nitroehydrocarbon!phase.

` ARTHUR; E; MARTIN REFERENCES CITED 5' A The following references4 are ofurecord in1 iiley of this'patent: y y

' STATES PATENTS" 

1. THE PROCESS OF RECOVERING MONO-NITROXYLENE FROM A PERSISTENT AND STABLE, SUBSTANTIALLY NEUTRAL, EMULSION THEREOF WITH WATER, SAID EMULSION CONTAINING FROM ABOUT 35 TO 65% BY WEIGHT OF NITROXYLENE, WHICH COMPRISES INTIMATELY CONTACTING SAID EMULSION AT A TEMPERTURE OF FROM ABOUT 35*C. TO ABOUT 100*C. WITH FROM ABOUT 10 TO 30% BY WEIGHT, BASED ON THE WATER CONTENT OF SAID EMULSION, OF SOLID SODIUM CARBONATE, IN AMOUNT SELECTED TO PRODUCE AN AQUEOUS SOLUTION WITH THE WATER CONTENT OF THE EMULSION HAVING A SPECIFIC GRAVITY GREATER THAN THAT OF THE NITROXYLENE UNDER THE CONDITIONS OF THE CONTACTING, THEREBY EFFECTING DE-EMULSIFICATION, AND RECOVERING A SEPARATED PHASE OF NITROXYLENE. 